학술논문

Synthesis and Characterization of Silica-Coated Cu$_{1-{\rm x}}$Ni$_{\rm x}$ Nanoparticles
Document Type
Periodical
Source
IEEE Transactions on Magnetics IEEE Trans. Magn. Magnetics, IEEE Transactions on. 48(4):1344-1347 Apr, 2012
Subject
Fields, Waves and Electromagnetics
Nickel
Copper
Nanoparticles
Silicon compounds
Magnetic resonance imaging
Hyperthermia
Curie temperature
microemulsion
nanoparticles
silica coating
Language
ISSN
0018-9464
1941-0069
Abstract
The synthesis of magnetic Cu$_{1-{\rm x}}$Ni$_{\rm x}$ nanoparticles was carried out in cationic water-in-oil (w/o) microemulsions of water/cetyl-trimethyl-ammonium bromide (CTAB), n-butanol/isooctane by the reduction of nickel and copper chlorides with hydrazine and NaOH. The synthesized Cu$_{1-{\rm x}}$Ni$_{\rm x}$ particles were heat treated to maintain their proper homogeneity and Curie temperature. Some alloy particles with the composition Cu$_{27.5}$Ni$_{72.5}$ were coated with silica prior to the thermal homogenization in order to retain the pristine morphology. The magnetic particles were characterized using XRD, transmission electron microscopy (TEM) and magnetic measurements. The thermal demagnetization in the vicinity of the Curie temperature of the nanoparticles was studied using a modified TGA/SDTA method.